UF2 bootloader for Trinket M0 in constant reset

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msivers
 
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Joined: Wed Sep 25, 2019 4:12 pm

UF2 bootloader for Trinket M0 in constant reset

Post by msivers »

Hello,

I have somehow managed to brick my SAMD21E18 board which uses the Trinket M0 bootlader.

I already had the board successfully running CircuitPython with a custom firmware based on the Trinket M0 UF2 file. The problems started when I uploaded a custom UF2 bootloader which I built from the repository below
https://github.com/adafruit/uf2-samdx1
After dragging the UF2 file onto the boot drive it was not recognized anymore as a flash drive when entering bootloader mode.
I then erased the board and reinstalled the Trinket M0 bin file from the link below via my J-Link.
https://github.com/adafruit/uf2-samdx1/releases
However, the board was still not recognized as a flash drive.
After trying to reflash the bootloader several times the board is now somehow stuck in a constant reset. When connecting the board the TRINKETBOOT flash drive appears but then the board immediately resets which continues indefinitely.

Using J-link I can still erase and reflash the bootloader but the result is always the same.
Does anyone have a suggestion how to unbrick the board?

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cchaubal
 
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Joined: Fri Aug 13, 2021 9:15 am

Re: UF2 bootloader for Trinket M0 in constant reset

Post by cchaubal »

I have this same problem. It was working fine all evening, and then all of a sudden it was not. Did I accidentally short a connection, and that somehow corrupted things? I notice it's been a while and no response on this thread, so hoping someone can provide some guidance on how to resolve this, if possible. Screenshot below of what I keep seeing every time I try to upload my code. The Trinket M0 works, but it just runs the program that I was last successfully able to upload - I can't update with anything new.
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Screen Shot 2021-08-13 at 8-13 6.12.48 AM .png
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adafruit_support_carter
 
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Joined: Tue Nov 29, 2016 2:45 pm

Re: UF2 bootloader for Trinket M0 in constant reset

Post by adafruit_support_carter »

@msivers You may have accidentally made changes to the fuse settings to get stuck in a constant watch dog timeout loop.

@cchaubal Were you also doing something with a custom bootloader?

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